A Guide to Stomach Cancer

Medically Reviewed By Faith Selchick, DNP, AOCNP
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Stomach cancer develops when stomach cells grow unmanageably. Early stages of stomach cancer may not cause noticeable symptoms, meaning it may be undetectable until it advances. Symptoms can include difficulty swallowing, abdominal fullness, and more. According to the American Cancer Society, stomach cancer comprises 1.5% of all new annual cancer diagnoses in the United States. Treatment may involve surgery, chemotherapy, radiation therapy, or a combination of therapies.

Read on to learn more about the types, symptoms, treatments, and risk factors for stomach cancer.

What are the causes of stomach cancer?

A man laying on his back with his hands on his stomach
Photography by Westend61/Getty Images

Experts do not yet fully understand the specific causes of stomach cancer. In general, cancer develops when cells begin growing unmanageably. These cells cannot grow as they should because their growth processes function improperly.

Researchers believe that a combination of genetic and environmental factors can trigger mutations that eventually lead to cancer.

Risk factors for stomach cancer

Stomach cancer may occur more often in people assigned male at birth or people who:

  • inherit conditions, including:
  • have certain medical conditions, including:
  • eat a diet high in smoked, salted, or cured foods
  • experience exposure to certain chemicals
  • have a family history of stomach cancer
  • had gastric surgery
  • smoke

Reducing your risk of stomach cancer

You may be able to lower your risk of stomach cancer by:

  • eating a diet high in fresh fruits and vegetables
  • limiting your intake of smoked, salted, or cured foods
  • quitting or reducing smoking
  • treating an H. pylori infection if you have it

What are the types of stomach cancer?

There are several types of cancers that can start in the stomach. Adenocarcinomas are the most common type, beginning in the inner lining of the stomach.

Other less common types include:

  • gastrointestinal stromal tumors
  • neuroendocrine tumors
  • lymphomas
  • squamous cell carcinomas
  • small cell carcinomas
  • leiomyosarcomas

What are the stages of stomach cancer?

An illustration of the growth of a stomach tumor
As stomach cancer progresses, it can penetrate deeper into and through the stomach wall. Illustrated by Jason Hoffman

Stomach cancer staging is complex. Doctors most often use the tumor, nodes, and metastasis (TNM) system to evaluate the size of the primary tumor and any spreading that occurs. They may use other staging methods, depending on where in the stomach the cancer starts.

Below is a simplified overview of the TNM stages of stomach cancer.

  • Stage 0: Atypical cells may be in the stomach lining, or cancerous cells may be in the top layer of the stomach’s inner lining.
  • Stage 1: This stage subdivides into stages 1A and 1B. The cancer spread involves layers below the top layer of the inner stomach lining and may involve a few adjacent lymph nodes.
  • Stage 2: This stage subdivides into stages 2A and 2B. The main tumor is in the deeper layers of the stomach lining and may affect multiple adjacent lymph nodes. The tumor may also be in the stomach wall.
  • Stage 3: This stage subdivides into stages 3A, 3B, and 3C. Doctors use these substages to classify cancer that may involve nearby organs or structures and may affect multiple adjacent lymph nodes.
  • Stage 4: This is the most advanced stage, when the cancer spread involves distant parts of the body.

What are the symptoms of stomach cancer?

The symptoms of stomach cancer may not become apparent until the later stages of the disease. As the tumor gets larger, it can interfere with digestion or swallowing. Because it takes up space in the stomach, a sense of fullness may occur shortly after a person starts eating.

Possible symptoms of stomach cancer include:

  • general sense of abdominal fullness
  • changes in bowel habits or bloody stool
  • difficulty swallowing
  • sensation of fullness, even without eating much or with a loss of appetite
  • indigestion or frequent belching or burping
  • nausea with or without vomiting
  • upper abdominal pain, which may get worse with eating

Nonspecific symptoms such as unexplained weight loss, fatigue, and weakness can also occur.

How do doctors diagnose stomach cancer?

If your doctor suspects stomach cancer based on your symptoms and risk factors, they may order one or more tests to confirm a diagnosis.

Imaging tests like CT scans, PET scans, or ultrasounds can allow doctors to evaluate your stomach for abnormalities. These tests can both narrow down areas that may require a biopsy and evaluate the extent of the cancer spread.

An upper endoscopy can allow your doctor to examine the stomach and nearby structures for areas of concern. They may also perform a biopsy at the same time, which allows for a definitive diagnosis.

Other tests may include:

  • blood tests
  • fecal tests
  • organ function tests

What are the treatments for stomach cancer?

The goal of treatment varies, depending on the stage of stomach cancer.

For early stomach cancers, the goal is to get rid of the cancer permanently. For more advanced stomach cancers, the goal of treatment may be to manage the spread of the disease, its symptoms or complications, and improve quality of life.

Early-stage stomach cancer may be curable with surgery. When surgery alone is not enough, chemotherapy may help shrink the tumor so that doctors can attempt surgical removal.

A combination of radiation therapy with surgery and chemotherapy may also be beneficial.

Immunotherapy and targeted therapy are also possible treatments. Doctors may use them in late-stage stomach cancer as palliative measures to reduce symptoms and extend life. Oncologists determine whether people are candidates for these therapies based on the pathology report of the tumor.

Other treatments for stomach cancer

Other therapies can help with your general health and complications of the cancer or its treatment, including:

  • medications to counteract nausea
  • blood transfusions to temporarily replace depleted blood components
  • dietary counseling to help maintain strength and optimize nutrition
  • pain medications as needed to increase comfort
  • physical therapy to help strengthen the body, increase alertness, reduce fatigue, and improve functional ability during and after cancer treatment
  • vitamin therapy to supplement vitamins not easily absorbed by the remaining stomach

What are the potential complications of stomach cancer?

Complications of stomach cancer include:

  • adverse effects of treatment
  • anemia, which is a low red blood cell count
  • ascites, or buildup of fluid in the abdomen
  • malnutrition
  • stomach wall perforation
  • severe hemorrhage
  • cancer spread

Other frequently asked questions

Here are a few other common questions about stomach cancer. Faith Selchick, DNP, APRN, AOCNP, reviewed the answers.

Is stomach cancer curable?

If doctors diagnose and treat stomach cancer early, it may be curable. Because symptoms may not appear until the later stages, doctors may not detect the cancer until it advances, making treatment more difficult.

What is the first sign of stomach cancer?

The signs and symptoms of stomach cancer can vary. They may include a feeling of abdominal fullness, pain, or changes in bowel habits. Some symptoms may be more general, like weight loss or fatigue.

Who is at the highest risk for stomach cancer?

People with a family history of stomach cancer, a diet high in salted or cured foods, or a history of smoking may be at an increased risk of developing stomach cancer. In addition, people with certain inheritable or acquirable medical conditions may be at a higher risk.


Prompt diagnosis and treatment for stomach cancer are essential to improving outcomes. If you think you may be at risk for stomach cancer based on your medical history or symptoms, contact your doctor right away.

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Medical Reviewer: Faith Selchick, DNP, AOCNP
Last Review Date: 2022 Nov 21
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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